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Treatment Process and Planning

Process Group

Our process and planning group conducts treatability studies, process selections, and plant evaluations and troubleshooting. Treatability studies include laboratory scale, 2 to 50 gpm pilot plants, and full-scale evaluations. They have selected the appropriate processes for small point of use applications up to treatment plants of several hundred mgd. Pilot testing includes all of the latest technologies and development of innovative procedures.

Bench and Treatability Experience

EE&T is a full service consulting firm that is known for its particular expertise in the area of conducting bench- and pilot-scale treatability studies. Our knowledge of scale down techniques comes from a strong background in process design by the firm’s managers. EE&T’s President, Dr. David Cornwell, P.E., was instrumental in the development of scale up/down to accurately define water plant conditions through simulation research. This work has been fundamental to much of the basic bench-scale work being undertaken today.

Since EE&T’s inception in 1985, it has designed and conducted numerous bench and pilot studies and this work has steadily increased to nearly 100 projects in all. EE&T recently completed the design and construction of a $1.2 million permanent pilot facility for ECWA in New York. EE&T’s treatability work over that time has been fairly evenly split between bench and pilot projects.

EE&T has extensive experience in designing and operating advanced treatment pilot plants. We were selected from a field of other nationally known firms to design and operate advanced pilot plants throughout the U.S. For example, we designed and operated ozone/BAC/GAC pilot plants for Tulsa, OK; Erie County Water Authority, NY; Appomattox River Water Authority, VA; Washington, NC; Marine Corps Air Station-Cherry Point, NC; and Durham, NC. All of these projects resulted in significant contributions to treatment, or resulted in design criteria for new processes.

EE&T has developed a specialist reputation over the years because of our experience in operating advanced pilot plants that include ozone, BAC, GAC, membranes, and high rate processes including DAF. Our firm has the equivalent of more than 100 months or 8 years of experience in running GAC and ozone pilot projects. We also have the equivalent of more than 2 years of operating experience in conducting membrane and dissolved air flotation pilot investigations. EE&T has vast experience in the operation of conventional pilot-scale projects.

Dissolved Air Flotation (DAF)

EE&T was one of the first U.S. firms to investigate the use of DAF for treatment of spent filter backwash water (SFBW) intended for recycle. In studying this application, our personnel visited numerous U.S. and European installations using DAF for potable water clarification or DAF used for residuals thickening. EE&T has recently completed a bench and pilot testing program for AwwaRF to evaluate DAF for treatment of spent filter backwash water. We believe that we are one of the only firms to regularly utilize bench-scale DAF equipment for this application.

Ozone

EE&T evaluated a number of alternative raw water oxidants, including ozone in a year-long pilot program using a state-of-the-art pilot plant designed by its engineers. Replacing raw water chlorine with ozone reduced TTHM and HAA5 levels without forming significant levels of bromate.

Membrane Treatment

EE&T has conducted several pilot-scale investigations of membrane treatment. EE&T completed bench and pilot-scale work in which membrane backwash intended for recycle was treated as part of an AwwaRF project. Bench-scale tests focused on screening various treatments to reduce solids levels before recycling and pilot testing was used to evaluate the impacts of recycling the untreated and treated backwash stream to the head of a microfiltration (MF) treatment process. EE&T evaluated a membrane system for treatment of spent filter backwash water as part of an AwwaRF project.

Granular Activated Carbon (GAC)

EE&T has conducted several pilot-scale investigations of membrane treatment. EE&T completed bench and pilot-scale work in which membrane backwash intended for recycle was treated as part of an AwwaRF project. Bench-scale tests focused on screening various treatments to reduce solids levels before recycling and pilot testing was used to evaluate the impacts of recycling the untreated and treated backwash stream to the head of a microfiltration (MF) treatment process. EE&T evaluated a membrane system for treatment of spent filter backwash water as part of an AwwaRF project

Softening

EE&T has conducted several pilot-scale softening studies including one for the Marine Corps Air Station located in Cherry Point, NC, City of White Sulphur Springs, WV, and the City of Tulsa, OK. Testing at Cherry Point included a pilot-scale evaluation of solids contact, spiractor softening treatment, and using pellet softening in combination with raw water prefiltered ozone.

Pilot Testing Facilities

EE&T has worked with all combinations of providing pilot facilities. We have worked with manufacturer based pilot plants, built site specific pilot equipment and provided the facilities on a lease or sale basis, designed and had contractor built facilities that were purchased by the utility or provided our own in-house equipment on a monthly rental basis. EE&T itself owns conventional pilot facilities—rapid mix, flocculation, sedimentation, and 4- or 6- in. diameter filters. We have an ozone generator and ozone columns and several sets of GAC columns constructed of glass and stainless steel for organics studies. EE&T also owns spiractor softening equipment.

EE&T owns on-line particle counters and on-line turbidimeters. We have set up several pilot facilities with automatic computer data logging. The trailer lab pictured was specifically designed for the purpose of providing laboratory and communication support at a remote facility. It was fully equipped with wet chemistry analytical equipment, batch particle counters as well as telecommunications equipment (fax, cellular phone, two computer/modem systems) needed to communicate and share data with our headquarters staff.